The thermodynamic properties for the CaO-CaF 2 , BaO-CaO and BaO-CaF 2 systems were calculated by molecular dynamics (MD) simulation using the simple Born-Mayer-Huggins type potential model. The interatomic potential parameters were determined by fitting the thermodynamic properties of pure CaO, BaO and CaF 2. The calculated thermodynamic properties for CaO, BaO and CaF 2 were in good agreement with measured results, and the superionic conductivity on the solid-solid phase transition of CaF 2 has also been successfully assessed by MD simulation. The ÁH M , ÁS M and ÁG M for each binary system were calculated based on the thermodynamic parameters obtained by MD simulation and thermodynamic solution model. The calculated enthalpy interaction parameters for the BaO-CaF 2 system represented the possibility of formation of the compounds such as BaOÁCaF 2 in the BaO-CaF 2 system. The calculated phase diagrams for the CaO-CaF 2 and BaO-CaO systems were in good agreement with experimentally measured and CALPHAD method results. The calculated eutectic points for the CaO-CaF 2 and BaO-CaO systems were about 20 mol% CaO at 1650 K and about 20 mol% CaO at 2050 K, respectively. The BaO-CaF 2 system has also been estimated the liquidus lines in the CaF 2-rich and BaO-rich region by MD simulation.

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The fault system of Liaodong Bay developed extensively under the control of the Tanlu Fault.The fault system can be grouped into strike-slip faults of grade I, trunk faults of grade II and branch faults (induced faults) of grade III respectively based on its developmental scale. The faults of grade I and II were deep, early and large while the faults of grade III were shallow, late and small. The formation, evolution and distribution features played a signifi cant role in controlling the migration of oil and gas in both horizontal and vertical directions. The fl uid transfer in the fault system occurred in the process of faulting. The strike-slip and trunk faults moved actively forming predominant pathways for oil and gas migration. The branch faults, with weak activity, generally controlled the development of traps and were benefi cial for the accumulation and preservation of oil and gas. The faults of grade I and II formed the major migration pathways for oil and gas, but their fault activity rates appeared to vary along their strikes. The zones with a relatively low fault activity rate might be favorable for oil and gas accumulation. When the activities of strike-slip, trunk, and branch faults came to a halt, the fault seal behavior had a vitally important effect on the accumulation of oil and gas. The controlling role of the fault over fl uid distribution was further analyzed by calculating the fault activity quantitatively.

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